The present invention consists of a conveying device with levers used in wrapping machines for delicate products like bars of soap which have just come out of a stamper. It has a device for gripping individual strips of material to wrap products. This invention is also of the type of wrapping machine provided with a conveying device.
Wrapping machines for delicate products have a large number of conveying devices. These consist essentially of many components whose function is to wrap the objects produced by the machine in suitable wrapping material.
Essentially, one of these components has a flat surface which accommodates a strip of wrapping paper, against which one side of the bar of soap is in contact, the wrapping material being fed in single strips by a feeding device. It has two levers to keep the side of the soap in contact with the wrapping material on the flat surface, while the machine moves the conveying device continuously or intermittently from a loading station to an unloading station. There are kinematic devices to maintain the correct movement of the device and its components from said stations.
In addition, there are devices for gripping the wrapping material, between which the products are wrapped to form the final product ready for sale.
The gripping devices work together with the feeding device which is housed in a first structure of the machine, and are assembled on the conveying device or arranged in a second fixed component of the machine.
U.S. Pat. No. 2,723,516 to Malhiot shows a wrapping machine equipped with a device for feeding strips of wrapping material integral with a fixed structure of the machine, and designed to place a strip of wrapping material on a conveying device prior to a bar of soap being deposited on it. A similar device transfers the strips on a conveying device only if the machine is working slowly; in fact, the transferral of the strips from the feeding device to the flat supporting surface of the conveying device can only take place in the correct fashion if the conveying device comes into contact with the feeding device for a sufficient length of time to allow the strip to be transferred from the feeding device to the conveying device, the bar of soap being placed in contact with the strip.
European Patent Application number 90103891.9 filed by the applicant is for a high-speed wrapping machine equipped with a large number of devices for conveying soap, having pincers for gripping the wrapping material coming out individually from a feeding device similar to that described for U.S. Pat. No. 2,723,516. Every conveying device of the European patent is equipped with a gripping pincer which is connected to kinematic devices which control it during the various phases of the machine's operation.
In the cases under consideration the gripping devices for wrapping material have the following disadvantages:
they are connected to kinematic devices which have only a single purpose;
they have an inertial mass which requires an increase in energy to make them work;
the kinematic devices to which they are attached must be perfectly in phase with the continuous or intermittent movements of the machine so as to permit the wrapping paper to be transferred in synchrony with the movement of the conveying device in the proximity of the feeding device.